Abstract: Objective To prepare a kind of immuno-colloidal gold chromatographic test strips to detect the human seminal specific protein P 30 from evidential substances in the forensic cases.Methods The mono clonal cell strains,which produce antibodies against various epitopes of human seminal specific protein P 30 as the antigen,were selected and their relevant monoclonal antibody proteins were isolated and purified from the ascites secreted by mice injected with the cells producing antibody proteins against each epitope.Colloidal gold was prepared and coupled with one of the purified antibody proteins so that the immuno-colloidal gold was obtained.Afterwards a piece of glass fiber was saturated with the new-prepared im muno-colloidal gold and then dried.A suitable kind of nitrate fiber membrane was chosen and coated at separate two places on it with the goat or sheep ' s anti-mouse IgG and another antibodies against an epi tope on the P 30 protein different from against which the antibodies coupled with colloidal gold are.Im muno-colloidal gold test strips were fabricated and their lowest detection limit,specificities were measured.Results The detection limit of the colloidal gold test strips is at least up to4ng/ml and a positive result is stilled observed when detected to a200000-fold dilution of mixed human seminal fluid from6persons,without non-specificity,that is,the strips only having reactions with the P 30 protein.Conclusions The col loidal gold test strips detecting human seminal specific protein P 30 can be applied in the determination of suspected human seminal substances in forensic examination.

Key words: human seminal specific protein P 30, colloidal gold, immuno-colloidal gold chromatographic test strips